Method of flotation of oxidized ores



Patented Mar. 27, 1934 UNITED STATES PATENT OFFICE.

METHOD OF FLOTAEON F OXIDIZED No Drawing. -Application November 1, 1928,Serial No. 316,632

11 Claims.

This discovery relates to a process of recovering values from oxide oresas distinguished from those of the sulfide type.

Throughout this specification the term oxidized ore, oxide ore, ornon-sulfide ore are intended to designate an ore in which the metalvalues are present substantially as non-sulfide compounds. In such oresthe metal values may occur as carbonate, sulfate, oxide, or as someother oxygenated compound of the metal. Such ores have usually beenformed in nature by oxidation of the original sulfides, andconsequently, they may contain small amounts of unaltered sulfides. Asfar as the present discovery is concerned, however, such sulfides arepresent incidentally.

The recovery of sulfide minerals by the flota tion process is now highlydeveloped and reagents adapted thereto are well known in the art.Heretofore, however,'the flotation concentration of oxide ores has beenvery unsatisfactory. Practically all of the proposed methods haveinvolved a preliminary sulfidization of the oxide component in anattempt to produce upon the surface of the mineral a coating of sulfidewhich would render it susceptible to ordinary sulfide flotationreagents. This sulfidization operation has proven very troublesome inpractice, partly because some of the oxide minerals sulfidize withdifllculty, if 30 at all, and partly because the sulfidizing reagentfrequently introduces complications and difiiculties in the operation ofthe flotation cell.

The essence of my invention is that I recover such oxide mineralswithout preliminary sulfldization by employing a reagent or combinationof reagents adapted specifically to the flotation of such oxideminerals.

Certain of the reagents specified in this application are well known inthe recovery of sulfides. It does not follow, however, that sulfidereagents are applicable to oxide flotation, and, as a matter of fact,there is no theory of reasoning by which one could conclude that asulfide flotation reagent would operate efllciently on oxides. Theentire history of the flotation art has shown that the reverse is true.According to prior practice, values present in non-sulfide form wereeither recovered by sulfidization or were lost with the tailings. In thepresent invention, however, by suitable selection of reagents, I amenabled to recover the non-sulfide minerals by froth flotation by theuse of a reagent combination adapted to the recovery of such specificminerals.

The reagents employed in flotation serve a number of specific purposesand may in general be divided into three classes: First, collectors orpromoters whose function is to collect into aggregates the mineral to befloated, and probably to attach such aggregates to the bubble; second,frothing agents whose purpose is to supply the bubble which is essentialfor the raising of the heavy mineral particles from the ore pulp; andthird, reagents known as conditioning reagents whose exact function isobscure but which probably serve a variety of purposes, such as freeingthe solution from soluble heavy metal salts which, if not so removed,would themselves consume the more expensive collectors, and possiblyalso to establish a proper hydrogen-ion concentration.

The use of such collectors as potassium ethyl xanthate, thiocarbanilidand the dithiophosphates.is old in the flotation of sulfide minerals.

I have discovered that the glycines in alcoholic solution andderivatives thereof, the xanthates and their salts when used incombination with a frother such as pine oil, the organic cyanamides andthe disubstituted dithiophosphoric acids and their salts are effectivein floating maximum concentrates of oxide ores.

The following tables show these reagents as i used with pulps containingthe red copper oxide cuprite, the blue copper carbonate azurite and thelead carbonate cerussite.

In all tests the operation was substantially as follows:

A 50 gram specimen of the ore was passed through rolls and ground on abucking board to pass through a 200 mesh screen. This sample was thenstirred for five minutes with 135 cc. of

distilled water in a small mechanically agitated centrate filtrate wasdetermined by taking 10 cc. thereof, plus the amount and concentrationof indicator specified in Clark on .The Determination of Hydrogen Ions,and comparing the color of the solutioniwith the color chart, all ofwhich is well known. The minimum and maximum pH value ran from 6.8 to9.4. 1

The results secured are tabled below:

Reagents lbs/ton Cone. Percent Test Ore gm Tails gr. Floated AF25 APG PxPOy .85 1 Cuprite. 5. 76 45.5 4.7 91.0 2 fin 1.44 1.28 42.2 6.8 84.4 3do 1. 44 a. 20 38.6 10. a 77. 2 4 Azurite.-- 2.88 47.7 2.0 05.4 5 do 1.44 0. 32 40. 0 v0. 9 98. 0 6 Corn its 1.44 48.7 0.6 97.4 7 5.0 47.5 1.805.0 8 0.43 0. 32 47.7 2.0 05.4 0 s 0.48 =1.c0 49.0 0.8 98.0

AF 25-Cresylic acid (25%) and diaryldithiostep of subjecting oxidizedore to a froth flotation phosphoric acid. operation in the presence ofphenyl glycine, cre- 9 0 APGAlcoholic solution of phenylglycine.

PX 0.54 lbs/ton pine oil and indicated amounts of K xanthate.

PCyPhenyl cyanamide.

From the above it will be seen that maximum values were recoverable withthese reagents operating upon the typical ores above specified.

While only certain derivatives and substitution products of the variousreagents are set out in the tables, and only certain oresare representedby the experiments described, yet obviously I do not wish to be limitedthereto, as my discovery is to be construed broadly to cover equivalentreagents and ores of which the above examples are mentioned merely forthe sake of illustration.

In the claims where I have specified oxidized ore I intend the same tocover ores which are substantially non-sulfide, in character and includemany so-called oxide ores which frequently contain 5% or perhaps moresulfide.

I claim: I

1. A process of flotation which includes the step of subjecting oxidizedore to a froth flotation operation in the presence of a glycine.

2. A process of flotation which includes the step of subjecting oxidizedore to a froth flotation operation in the presence of an alcoholicsolution of a glycine.

3. A process of flotation which includes the step of subjecting oxidizedore to a froth flotation operation in the presence of phenyl glycine.

4. A process of flotation which includes the step of subjecting oxidizedore to a froth flotation operation in the presence of a glycine and adisubstituted dithiophosphate.

5. A process of flotation which includes the step of subjecting anoxidized ore to a flotation operation in the presence of a flotationreagent taken from a group of organic amino acids consisting of glycinesand phenyl cyanamid.

9. A process of recovering ore values from crude ores, which comprisesthe step of subjecting the crude material to a froth flotation operationin the presence of a promoter having the probable formu1a where R. is agroup selected from a class consisting of CN and carboxylic acids. l

10. A process of flotation which includes the step of subjecting anoxidized ore to a froth flotation operation in the presence of aflotation promoting reagent consisting of an amino substituted phenylcompound containing an acid residue selected from a group consisting ofCN and COOH. 7

11. A process of flotation which includes the step of subjecting anoxidized ore to a froth flotation operation in the presence of aflotation reagent selected from a group consisting of phenyl glycine andphenyl cyanamide.

I LUDWIG J. CHRTISTMANN.

